Sorry to lose a good player, BoP!

Questions about my upcoming game

I'm debating a few things about my upcoming game (not the next one now, but probably in January sometime). For those of you interested in playing, I'd like to know a few preferences to try to increase the player count.
Some background: cult-game with some powered characters but mostly vanilla. Unless we have a lot of players, starting with 1 Cultist but their power prevents a D1 Town wins. (It's not a "survives first death", but similar, kinda.)
I'm doing no private communication between townies as the default.
Day Phase ends with killing the lynchee. Night phase folk use powers (if any) and cult has to convert someone. (If the cult is entirely inactive, I'll use RNG to convert someone.)

Questions
1. Would you prefer the potential power roles be declared ahead of time?
2. If yes to #1, would you like full descriptions of their powers or just hints?
3. If yes to #1, would you like me to state which ones make it into the final game?

4. What do you think of a Town power role that allows 2-3 people to make a QuickTopic? Will probably be able to use watch/track power instead, in case doesn't feel like networking.
5. What do you think of the Cult knowing who is Cult, but not being able to communicate privately?
6. What do you think of a Town power that is effectively being a Spy? That is, if converted, they learn some about the Cult (and, if it has a QT, join it), but are really Town. I think this would only be feasible if the Cult can kill itself (akin to Aventine's Witch Hunt game) or the Cult doesn't have a QuickTopic, so that there's a risk to the Spy just publicly declaring who's a cultist.
If a Spy-type role exists, I think it's only fair to state it exists before game starts, even if the details about other power roles are hidden.

7. For a cult game, what's the opinion on a town vigilante power and/or a serial killer role? (SK probably only if a fair number of players. Considering a serial killer and survivor neutrals.)